Electric motor



April 13 1926.

H. K. SANDELL VI'ELECTRIC MOTQR Original Filed August 17, 1922 2 Sheets-Sheet 1 A fizz/677703 52 67? I 'jam/e i April 13 1926'. 1,586,682

H. K. SANDELL ELECTRIC MOTOR Original File ugust 1'7. 1922 2 Sheets-Sheet 2 Patented Apr. 13, 1926.

UNITED S T A T E S 1 Oil?! ELCE...,

HENRYKPSANDELL, on OHICAGQILLINOIS, assrenon no Min s 'novnntr z COMPANY,

or CHICAGO, ILLINOIS, A conronarron on IL InoIs;

ELECTRIC MOTOR.

Original application filed August 17, 1922, Serial No.'582,458." Divided fana-thisapplication;filediJ'une;

20,1924; Seria1:N0..721,Z12; Y

To all'whom 'it may concern:

Be it known that I, HENRY K- SANDELL, a citizen ofthe United States, residing at Chicago, in thecounty of Cook and State of Illinois, have invented a new and. useful Improvement in Electric Motors, of. which thefollowing is a specification. r

This invention relates particularly to motors. The improved motorherein shown and described, while it may be employed for other purposes, is well adapted for use in musical machines employing stringed instruments of the violclass, where the motor. may

serve to operate the bow-shafts at varying speeds.

The present application illustrates one use of'the improved motor in connection witha musicalinstrument of the character mentioned, and constitutes a division of my ap* plication No. 582,458, filed in'the United States Patent 'Office, August 1'7, 1922- The invention willlbe understood withreference to the accompanying drawings, in Which?- Fig. 1 is a vertical'sectional View through theimproved bow-motor; 2-is a horizontal sectional View throughthe bow-motor on the line 2-2 of Fig.1; Fig. 3is a vertical sectional View on the line 33'of- Fig. 1; and;Fig. 4 is a diagrammatical view illustrating the circuits which may be employed in connection with the invention.

Referring to the'drawings, Fig. 4c; shows diagrammatically certain elements of an electrically operated stringed instrument of the viol class, one of' the fingering levers, designated 14, and one of the bow-depressing levers, designated 22, being shown. The string of the violin or other instrument is designated 12.

Above each string12 is a bow member or sounder 15 preferably formed ofnested conical celluloid shells, thesesounders being secured to' the ends of the bow shafts 16, which" extend. in a direction substantially longitudinally of the strings 12. These bow shafts 16 pass through a journal or hearing formed in the sleeves 18 which partially surroundthe worm 19, the sleeves, 18 being rotatable for a limited distance upon the worm gear, 19. At their ends the bow shafts 16 are provided with'gears 20 which mesh withand are.driven,by the worm 19." The worm, 19 His journaledfin bearings suitably provided in a housing21 supportedon the bow :motor casing, as hereinafter; morefully described. From the above description it.

willube-seen that the bow shafts-'lfiimay zbe depressed to bringthe rsounders. 15- into' en gagement with the corresponding strings. Suitable means are provided for this pur pose. EOl."6XiLI1lPl6, the leve1.s -22;;1nay be employed, these levers;being-act 11&ted byele'ctrmmagnets 255 when 7: the latter are energized to depress the corresponding bow shafts 16.

Theimproved bowp inoton will be more fullydescribed; The wormal9 'whichrm tates "the bow shafts: 16 is. connected: di:

rectly through shaft; 26 with'ithe rotor 27.

of the'A; C. induction; motor, 28, ,which is housed in; a. casingi29 supported =on the standard BO. Ther0tor.='27is:of the indu U011 motor? type, provided IL'VV'lllll la 2 squirrel cage 29%; The .staton 30, which' isiformed .of laminated sheets of: a: suitable iron, isrpmr videdwithithe teeth 32whiclrformthe poles The stator teethw32zaifl v ofthe motor. vlded into quadrants, each: 1 containing; an

equal. number of 'teeth, the quardantsflbeing separated by-the "1366151133. A:set;:.0fnfO T: pole windings 3 1, whose coils are connected in .1 series-as.- shownrin :Fig1a6, are provided, these; windingsvpassingw around; thehteeth 32 of each quadrant andi'being separated by the teethi 33. A isecond-zset of; bipolar windings 351 are provided, 5 whose coils are likewise conncctedi in series, these windings each passing aroundi' the teeth of, two sets of successive quadrants. and; the included tooth- 33 'and being; sp aced apart, 'by rthe, a1r ternate teeth Thefour-polewindings are preferably formech of a. greaterwnumber of windings of smaller wire than the; bipolar windings.. Athird setofvwindings 36 :is provided within the bipolar windings, these windings each-passingaround one of the windings alone.

normal operation, a controlled speed of rotation of the bow shafts is secured by means of the four-pole windings 34, the polarity of which is then caused to be dominant. A more rapid rate of rotation is secured by passing the current through the bipolar If a slower rate of rotation and a lower volume of tone are desired, the phase windings 36 are placed 111 shunt with the other windings, through which current flows in series as in normal operation.

The operation of the device is more clearly illustrated by Fig. 6, which shows diagrammatically the electrical interconnection of the various parts, which are here given the same numerals as in the preceeding figures of the drawing.

Two main lead lines 40 and 41 are provided for the operating current, which 1n the present instance, is an alternating current. The normal operating current, for rotation of the bow shafts at a normal rate to produce a normal volume of tone, the current connection is from line 40 through the branch line 42 to the four-pole coils 34, through which the current passes in series. From the four-pole coils I 34 the current passes through the connection 44 to the b1- polar coils 35, through which it passes 1n series- From the bipolar coils 35, the current passes directly into the lead line 41. As the bipolar coils 35 are constructed of fewer coils and of larger wire than the four-pole coils 34, the flux produced by the latter is dominant and a normal rate of rotation is produced.

V In order to produce a louder tone, suitable'means are provided for increasing the rate of rotation. of the -motor. For example, the current may pass from the line 40 into the'contact roll 45. A perforated note sheet 46 passes over this contact roll. When a suitable perforation is provided in the note sheet, contact is made between the roll and the contact member 47, and current then passes through the line 48 which is directly connected to the connection 44 between the four-pole coils 34 and the bipolar windings 35. Current then passes through the two bipolar windings 35 in series and thence to the line 41. The four-pole windings 34 are thus shunted out of the circuit and the polarity of the stator of the motor is determined by the bipolar windings 35, with a consequent increase in speed of the rotor. In manual operation, the same effect may be produced by passing the current from the line 40 throu h the line 40*, the pedal contacts 45 and 4 and the connector 48, which is directly connected to the line 48 leading to the bipolar windings 35.

For slower rotation of the rotor of the motor and a lower volume of tone, current passes from the line 40 into the contact roll 45, through contact 49 when a suitable perforation is provided, thence through connee-tor 50 to the split phase windings 36, through which it passes in series. From the split phase windings 36 the current passes through a connector 51 to the line 41. Instead o'l employing the contact rollers 45 and the contact 49, this circuit may likewise be closed through the line 40, the pedal 45, pedal contact 49 and line 50. It will be noted that there is always a connection through the four-pole windings 34 and through the bipolar windings 35 in series at all times, unless modilied by the action of the control contacts. Consequently, when current passes through the contact roll 45 and the contacts 49 or through the corresponding pedal contacts just referred to, the circuit through the split phase windings 36 is in shunt with the circuit through the windings and 35. Consequently, current at this time passes through all of the windings, that through the split phase windings being in shunt and the rate of rotation of the rotor is materially decreased. The note playing circuits are controlled independently of the circuits through the windings of the motor controlling its speed. For example, when contact is made between the contact roll 45 and the note playing contact member 52, current-passes through the connection 53 to the fingering magnet 14, thence through contact 54 to the bow shait depressing electromagnet 25 and from this electromagnet through the connection 55 to the line 41. This circuit operates without affecting the circuit through the bow motor.

The improved motor has been described as applied to the actuation of a bow shaft of a stringed instrument and as controlled by a music-sheet, but no unnecessary limitation should be understood therefrom, but the appended claims should be construed as broadlyas permissible in view of the prior art.

I claim:

1. In an alternating current motor, a squirrel cage rotor, a stator having individual sets of four-pole windings connected in series, bipolar windings connected in series and split phase windings connected in series, connections joining the four-pole windings and the bipolar windings in series, means for cutting out the four-pole windings to impart an increased rate of rotation to the rotor, and means for permitting passage of a shunt current through the split phase windings to decrease the speed of rotation of the rotor.

2. In an alternating current motor, a squirrel cage rotor, a stator having individual sets of four-pole windings connected in series, bipolar windings connected in series and split phase windings connected in series, means for permitting passage of current either through the four-pole windings and the bipolar windings in series or through the bipolar windings alone, and means for permitting passage of a shunt current through the split phase windings to decrease the speed of rotation of the rotor. 3. An alternating current motor having a squirrel cage rotor, a stator having independent sets of windings, one set forming a greater number of poles than the other, a third set of windings out of phase with the first-mentioned sets of windings, means permitting passage of current normally in series through the first-mentioned sets of windings, independent means for cutting out one of said sets of windings, and means for permitting the passage of current through the third set of windings in shunt with the first-mentioned sets of windings.

4:. In an alternating current motor, a

squirrel cage rotor, a stator having independent sets of windings, one of said sets of windings forming twice the number of poles formed by the other set and being wound to produce a stronger magnetic flux, and means permitting passage of current normally through both sets of windings irr series.

5. In an alternating current motor, a squirrel cage rotor, a stator having independent sets of windings, one of said sets of windings forming twice the number of poles formed by the other set and being wound to produce a stronger magnetic flux, means permitting passage of current normally through both sets of windings in series, and means for cutting out the set of windings forming the greater number of poles to vary the speed of the rotor.

HENRY K. SANDELL. 

